#ifndef _MY_STRING_H_
#define _MY_STRING_H_
#define NULL (void *)0
typedef unsigned long my_size_t;

my_size_t my_strlen(const char *s);

char *my_strncpy(char *dest, const char *src, my_size_t n);

char *my_strncat(char *dest, const char *src, my_size_t n);

int my_strcmp(const char *str1, const char *str2);

#endif
